The construction documents must designate the number of occupants to be accommodated in all rooms and spaces, except in which occupancy?

In commercial building codes, the requirements for designating the number of occupants in various occupancy types are based on the nature and use of those spaces. The correct answer indicates that the "M" occupancy classification, which pertains to mercantile spaces, does not require specific occupant load designation within the construction documents.

The rationale behind this is tied to the characteristics of mercantile use. Mercantile spaces are typically retail operations where customer interaction is expected, such as stores and markets. The occupant load can fluctuate considerably based on shopper volume and is not fixed. Therefore, these spaces generally have more flexibility in accommodating varying numbers of occupants at different times.

In contrast, the other specified occupancy types (R-2 for residential apartments, A-1 for assembly areas with fixed seats, and F-1 for factories) have more defined requirements regarding occupant load because their uses are more predictable and controlled. For these types, the occupant load must be calculated and documented to ensure safety, comply with fire codes, and facilitate emergency planning and egress.

Thus, the absence of a requirement for a designated number of occupants in mercantile spaces allows for adaptability in design and operation, accommodating the dynamic nature of retail environments.